Transcritical CO2 Rankine Cycle Engine expander systems can be utilized for recovering heat energy from a number of heat sources, from the waste heat of automobile combustion processes (e.g., exhaust heat), to the combustion of waste materials, solar energy, and many other heat sources. However, efficiencies of this process have been less than desirable. An improved process and design for recovering such heat is desirable.
Furthermore, the transportation technology industry employs as its dominant chemical energy conversion device of choice, the internal combustion engine (ICE) using the Otto or Diesel cycle. Some experimental turbine powered vehicles were built as test cases but they proved lower in efficiency and had higher manufacturing costs due to material requirements necessitated in gas turbine engines. The Gas turbine engine found its best application in aircraft due to a high power to weight ratio permitting more freight for the same design. Central power generating stations use a turbine expander due to a high demonstrated torque conversion efficiency usually in the range of 85%. The downside to turbine expanders is they require a high volume of gas to run efficiently. Therefore they do not lend themselves to very low power conversion systems much under significant fractions of a megawatt.
The energy balance is a metric of performance for vehicles such as passenger cars, which can be a useful means of grasping the percentage of the fuels energy content, being utilized in actually moving the passenger car along a chosen road. For primary passenger cars using only an ICE, the percentage of input energy delivered to the transmission is approximately 22-36% for a gasoline powered car and 42% for a Diesel. The energy lost to stop-start cycle's, cuts that amount to less than 13% for gasoline cars and under 20% for passenger Diesel cars.
In recent years hybrid electric cars have shown dramatic improvements to the energy utilization by averaging the fluctuations in stop start cycles. Thereby raising the miles traveled per gallon of primary fuel, and simultaneously lowering emissions per mile by the efficiency improvement. The improvement was the result of converting the fuel into stored electricity by having the ICE drive a permanent magnet alternator, which then charged a storage device such as a Lithium ion battery. Still the improvement can only approximate the ICE efficiency, no matter what the vehicle application was, whether it was a heavy truck, train, ship or aircraft.
Furthermore, economic instability has placed a greater demand on the performance of energy extraction devices. Notably Transportation technology has had pressure from two fronts, the cost of operation and the simultaneous demand of environmental impact reduction.
An improved process for solving one or more of the above identified problems is desirable.